1. Field of the Invention
The invention pertains to vehicle safety systems sensing the operator""s weight upon the vehicle seat and is characterized by its simplicity of construction, ease of assembly and disassembly, and ability to sense a shifting of the operator""s weight upon the seat.
2. Description of the Related Art
A number of vehicle safety systems utilize an electric switch which senses the operator""s presence upon the vehicle seat whereby desired vehicle functions can be rendered inoperative if the operator is not seated.
Such vehicle safety systems may include a switch mounted in the central region of the seat lower panel, or a switch sensing the position of the seat support structure, and includes an upwardly extending or moving switch actuator which is depressed by the operator""s weight and is released when the operator""s weight is removed from the actuator. One of the problems encountered with this type of switch controlled vehicle safety systems arises from the fact that if the operator""s weight laterally shifts on the seat, the electric switch may operate even though the operator is located on the seat and desires normal vehicle operation. Such inadvertent safety switch operation due to the operator""s weight shifting on the seat is troublesome, inconvenient and may raise safety concerns.
Another problem that arises with vehicle seat safety systems utilizing electric switches mounted in the lower panel of a vehicle seat results from difficulty in assembling the electric switch into the seat, or removing the electric switch for maintenance and replacement purposes. Vehicle seats usually include foam cushions or covers integrally attached to the seat pan and back, and it is difficult to directly incorporate the electric switch into the seat structure in such a manner as to permit easy switch installation and removal. Accordingly, in many vehicle safety systems utilizing electric switches operated by the operator weight, the switch is located exteriorly of the seat necessitating a vertically movable seat support, which may not be desirable.
It is an object of the invention to provide a vehicle seat safety system for use with cushioned vehicle seats which employs an electric switch mounted within the seat bottom or lower panel, and wherein the electric switch will sense the operator""s weight even though such weight is laterally displaced upon the seat.
Another object of the invention is to provide a vehicle seat safety system wherein an electric switch is directly mounted in the seat lower panel and may be inserted into the seat panel, and removed therefrom, from the lower side of the seat panel without necessitating special tools or disassembly of the seat, and yet the electric switch will be positively maintained in the desired operative position.
The vehicle safety system in accord with the invention is associated with the lower panel of the seat pan and may be utilized with vehicle seats of various configurations with or without back rests.
The seat bottom consists of a lower panel, usually stamped of metal, and a foam cushion is supported by the lower seat panel. The seat lower panel includes upper and lower sides, as well as a central region, lateral sides and a forward and rear region.
An opening is defined in the seat lower panel central region equally spaced between the panel lower sides, and an electric switch having an upwardly extending actuator located upon the switch is mounted within the panel opening. Vertical movement of the actuator operates the switch.
An actuator plate is superimposed over a significant portion of the upper side of the seat lower panel central region, and over the switch actuator. Preferably, the actuator plate is formed of a resilient material, such as spring steel, and is bowed upwardly so that the portion superimposed over the switch actuator is normally out of engagement with the actuator, and the actuator plate includes a forward edge disposed toward the lower seat panel forward region, and the actuator plate also includes a rear edge disposed toward the seat panel rear region. The rear edge of the actuator plate is formed with a pair of hinged projections which are received within openings defined in the seat lower panel forming a hinge for the actuator plate and maintaining the actuator plate in its desired position over the electric switch and its actuator.
The actuator plate is located below the flexible seat cushion wherein weight on the seat cushion depresses the actuator plate operating the switch actuator. In order that the electric switch will always sense the presence of the operator""s weight, extensions are defined on the lateral sides of the actuator plate extending toward the seat lower panel lateral sides. These actuator plate extensions render the actuator plate sensitive to the operator""s lateral movement upon the seat permitting the switch to sense the operator""s presence upon the seat even though the operator""s weight significantly shifts laterally on the seat for whatever reason.
The opening for receiving the electric switch located within the central region of the seat lower panel is of a general xe2x80x9ckeyholexe2x80x9d configuration, i.e. includes a larger portion intersecting an elongated smaller portion. The opening larger portion is of such dimension in relationship to the dimension of the electric switch body to permit the electric switch body to be inserted through the opening large portion, actuator first. The switch body includes a smaller dimension and a ledge or shoulder is located between the switch body larger and smaller dimensions. Upon inserting the switch body through the large dimension, which also accommodates the shoulders, the switch body may be laterally moved into the opening smaller dimension toward the lower panel rear region with the switch body shoulders being located above the lower panel opening. The smaller dimension portion of the opening permits the switch body shoulders to overlie the edges of the smaller dimension opening preventing the switch body from being pushed through the lower panel, and small stop shoulders defined in the neck of the opening small dimension cooperate with the configuration of the switch body to prevent lateral movement of the switch body toward the opening large dimension during vehicle use.
Accordingly, the switch may be quickly installed within the lower panel opening by aligning the switch body and its shoulders with the opening larger portion and pushing the switch therethrough, laterally displacing the switch body over the opening smaller dimension, and lowering the switch into the opening smaller dimension permitting the switch body shoulders to rest upon the upper surface of the seat lower panel. Removal of the switch from the seat lower panel requires the reverse procedure of that previously described.
Excessive pressure upon the switch actuator is prevented by bosses defined in the seat lower panel extending upwardly from the seat panel upper side which will be engaged by the switch actuator plate to prevent excessive depression of the actuator plate.
The vehicle seat safety system of the invention provides an economical manner for mounting an electric switch directly within a seat lower panel, permitting the switch to be installed, or removed, from the seat lower panel quickly and without harm or disassembly to the cushioned portion of the seat. Further, by the utilization of the actuator plate lateral extensions, the electric switch will sense the operator""s weight even though such weight has been laterally displaced on the seat due to turning, the operator leaning laterally, or otherwise shifting his weight.